The overall goal of this SCOR is to carry out a cohesive, interdisciplinary program of investigation designed to improve the diagnosis, management and prevention of the adult respiratory distress syndrome by identifying the causes, mechanisms and sequence of acute lung injury. To foster achievement of this goal, the SCOR will establish collaborative arrangements among experienced investigators already pursuing, independently, fundamental and clinical research which is relevant to the SCOR goal. In developing this proposal, care has been taken to include only investigators who are already engaged in such relevant research, only projects which relate to each other in a cohesive manner, and only individuals who can interact effectively within a SCOR environment dedicated to close and sustained interaction between fundamental and clinical disciplines. The resultant SCOR incorporates scientists from the disciplines of immunology, biochemistry, pathology, thoracic surgery, hematology, and pulmonary medicine, all of whom will focus their investigative efforts on factors which may: (1) be responsible for the induction or potentiation of acute lung injury; (2) allow prediction of the sequence of lung injury and repair; or (3) improve the detection of treatable causes of acute respiratory failure due to lung injury. Specifically, four projects areas have been identified which involve animal and human investigations dealing with: (1) the potential participation of Hageman Factor components and components of the complement system in the inflammatory reaction in the adult respiratory distress syndrome (Dr. Charles Cochrane); (2) the behavior of surfactant phospholipids in patients with ARDS (Dr. Louis Gluck); (3) the role of blood platelets and polymorphonuclear leucocytes in the induction or potentiation of acute lung injury (Dr. Roger Spragg); and (4) studies of the yield and risk of various diagnostic approaches to the identification of infectious agents in the patient with acute respiratory failure (Dr. Kenneth Moser). Each of the Projects will interact with a Clinical Core Unit based in the Active Medical-Respiratory Care Unit of the University. This unit has extensive experience in the diagnosis and management of ARF and enjoys close ties with the Burn and Trauma Centers at University Hospital and the Respiratory ICU at the San Diego Veterans Hospital. T (Text Truncated - Exceeds Capacity)